The present invention is directed generally to electrically conductive composites containing polyacetylene and high nitrile polymers. The invention relates to the preparation of electrically conductive composites such as polyacetylene in a high nitrile polymer matrix that can optionally contain mono-ethylenically-unsaturated comonomers, conjugated diolefins or mixtures thereof. In another aspect, the invention relates to novel electrically conductive composites, which composites are environmentally stable, exhibit solvent resistance and have good uniformity of dispersion.
Conductive polymer are highly sought after at the present time to serve as substitutes for metals in a variety of applications conducting electricity. Many varieties of electronically conductive polymers are known in the art. These compositions have varied in their polymer structure and have included conductive components of polyacetylene, polypyrrole, poly-p-phenylene and poly-p-phenylene sulfide. Polyacetylene is a material of considerable interest because it can be rendered highly conductive by treatment with a variety of electron donors or acceptors. However, these organic polymer compositions lose stability under ambient conditions, rapidly lose their conductivity when exposed to ambient atmosphere, have poor mechanical properties and poor processability. There exists a need for develop conducting polymers with improved properties.
A current approach as found in M. E. Galvin and G. E. Wnek, J. Polymer Sci., Polymer Chemistry Ed. 21, 2727 (1983), and U.S. Pat. No. 4,394,304 involves the in situ polymerization of acetylene in polymer films of low-density polyethylene, impregnated with a catalyst. These composites have good mechanical properties and conductivities. These composites, however, suffer from inadequate air stability in that the conductivity dramatically decreases over a short period of time upon exposure to air. Furthr, these composites suffer from poor uniformity.
It is an object of this invention to provide electrically conductive composites comprising polyacetylene and high nitrile resin. It is another object of this invention to provide electrically conductive composites that are environmentally stable when exposed to ambient atmosphere. It is another object of this invention to distribute the polyacetylene uniformly throughout the electrically conductive composites. It is another object of this invention to provide lightweight and inexpensive devices for electromagnetic interference shielding.
These and other objects, together with the advantages over known methods, shall become apparent from the specification which follows and are accomplished by the invention as hereinafter described and claimed.